cmos compatible integrated dielectric optical waveguide coupler and fabrication jeong-min lee...

CMOS Compatible Integrated Dielectric Optical Waveguide Coupler and Fabri-

cation

Jeong-Min Lee

([email protected])

High-Speed Circuits and Systems LAB.

2011-2 Special Topics in Optical Communications

mailto:[email protected]

High-Speed Circuits and Systems LAB. 2

Information

Name: CMOS Compatible Integrated Dielectric Optical Waveguide

Coupler and Fabrication

United States Patent (Patent NO.: US 7,738,753 B2)

Date of Patent: Jun 15, 2010

Inventors: Solomon Assefa

Assignee: IBM



Contents

1. Background of the Invention

2. Summary of the Invention

3. Fabrication Process (Detailed description)

4. Conclusion



Background of the Invention

Integrated semiconductor devices that include one or more photonic devices: Photodetectors, Modulators, and Optical switches Require a mechanism to couple optical signals between the opti-cal fibers and the silicon based waveguides

Coupling from an optical fiber to a photonic device with input and output waveguides often suffers from loss due to index and mode-profile mismatches Polymer couplers – Technique used to minimize losses in coupling– Provide effective matching

Optoelectronic circuits (fabricating CMOS) Fabricating polymer couplers for use photonic devices need to be encapsulated and annealed as CMOS-compatible processes



Summary of Invention

This invention provides a method for encapsulation of the devices and the formation of the couplers Performance is not affected

This invention provides a CMOS compatible method:– Thermal treatment– Electrical activation– 3D integration of optical devices

This invention allows an efficiently manufactured semiconductor de-vice that integrates photonic devices with CMOS circuit devices.



Fabrication Process

1. Accept a semiconductor device with an Integrated Optoelectronic circuit and at least one waveguide (Fig. 1)

2. Depositing a lower SiN layer, an SiON layer, a DLC layer and an upper SiN layer (Fig. 1)



Fabrication Process

3. Deposit photo-resist layer with an etching area defining an optical wave guide coupler fabrication area (Fig. 1)

4. Etch a portion of the upper SiN layer under the etching area (Fig. 2) DLC: CMP Stop Layer



Fabrication Process

5. Remove the photo-resist layer and a portion of the diamond like carbon(DLC) layer under the etching area (Fig. 3)

6. Etch the SiO2 layer to at least the lower SiN layer (Fig. 4)



Fabrication Process

7. Depositing an SiON layer onto the semiconductor die (Fig. 5)

8. Perform CMP to remove the SiON layer not within the etching area and the upper SiN layer (Fig. 6)

CMP: Chemical Mechanical Polishing



Fabrication Process

9. Etch the DLC layer to leave the SiO2 layer and SiON transition layer (Fig. 7)

10. Semiconductor die that has been cleaved along cleave line to ex-pose an exposed face of the SiON coupler (Fig. 8)

11. An optical fiber is attached to the exposed face of the SiON coupler



Conclusion

This invention provides a method for encapsulation of the devices and the formation of the couplers

Polymer couplers – Low losses in coupling– Provide effective matching

photonic devices need to be encapsulated and annealed as CMOS-compatible processes


Thank you for listening

Jeong-Min Lee

([email protected])

High-Speed Circuits and Systems


cmos compatible integrated dielectric optical waveguide coupler and fabrication jeong-min lee...

Documents